Devices for preparing and administering bone cement are known that comprise two separate chambers in which the two components that make up the bone cement are stored, said components typically being a liquid component and a powdered component. As known, in order to obtain an effective application of the bone cement during surgery, such two components must be mixed on the spot, i.e. in the operating room when the operation is being carried out.
In some known devices the liquid component is enclosed in a hermetically closed container, like for example a glass vial, so as to maintain the sterility of the component itself and to avoid it being lost into the atmosphere, since it is particularly toxic to people in the operating room. The aforementioned container is usually housed in one of the two chambers of the device and is opened or broken at the moment of use, so that the liquid itself then flows, in a spontaneous or forced manner, into the chamber in which the powdered component is stored to mix with it.
The bone cement thus obtained is dispensed through a mobile piston inside the mixing chamber, through a suitable opening.
In known devices the mixing of the two components, after they have been brought into contact with each other in the way described, can take place by manual shaking by the operator, or else by using a special mixing member, which acts inside the chamber in which the two components are located.
In order to make it easier to mix the two components, in some known devices the mixing member is positioned coaxial to the dispensing piston and on the opposite side with respect to it: this arrangement of the components allows the device to be held securely and comfortably during the actuation of the mixing member.
At the same time, such an arrangement of components, for reasons of practicality, simplicity and cost-effectiveness of production, requires the dispensing of the mixture to occur from the same opening through which the mixing member passes and is actuated.
In some known devices, at the end of the device with which the mixing member is associated, there is a cap to which the member itself is connected. At the end of the preparation of the mixture, it is necessary to remove the cap together with the mixing member in order to be able to dispense the preparation thrusted by the piston. This last operation, as well as being cumbersome and not very practical during surgery in an operating room, is not without drawbacks.
Firstly, indeed, there is a high probability of the preparation, when exposed to the air, contaminating, becoming unsuitable for application.
Secondly, it can accidentally come out from the device placing the health of the people present in the room at risk due to its high toxicity, and requiring a series of other provisions and safety measures to protect these people.